Rigorous software design for nano and micro satellites using BIP framework

The CubETH satellite mission, a cooperative Swiss CubeSat mission involving ETH Zurich, EPF Lausanne, several universities of applied sciences, and Swiss companies, will allow technology demonstrations and proof-of-concepts concerning GNSS-based navigation information by carrying five patch antennas, each connected to two independent u-blox NEO-7N receivers. These very small, commercially available low-cost receivers are able to track single-frequency code and phase data of all the major GNSS, i.e. GPS, GLONASS, QZSS, Galileo and Beidou. The main science objective for the CubETH mission is to investigate precise orbit determination strategies using COTS hardware. The mission shall also demonstrate new technologies, applicable in the field of small satellites. In this work, we focus mostly on development of robust flight software for small and nano satellites. During the Swisscube project there were numerous problems with validation and verification of the flight software code. The software has to be adapted to the hardware architecture selected for every new satellite mission. While commercial tools exist to help with the issue, subject of robust software development was not addressed by the cubesat community, mostly due to lack of resources. Some projects simply structure their code in C/C++ and then extensively test it, maybe using some analysis tools such as "Lint" [5]. This is an helpful tool to find some design errors, but it does not guarantee that the software behavior is the desired one. Others use SysML/UML tools to describe the system as a whole and then check some properties such as energy consumption. SysML can be a valid tool for system engineering as a whole, but it is not rigorous enough to allow automatic software behavior verification and validation. In this project the “Behavior Interaction Priority” BIP framework will be used to design the software running in the control and data management subsystem (CDMS) of CubETH. The BIP framework has been developed by the Verimag laboratory in Grenoble university and is currently used in the EPFL by the "Rigorous System Design Laboratory" (RISD). We have designed and modeled a full software architecture using this framework to formally verify our software. We will present lessons learned and problems that were encountered during the development

Contact-based navigation for an autonomous flying robot

Autonomous navigation in obstacle-dense indoor environments is very challenging for flying robots due to the high risk of collisions, which may lead to mechanical damage of the platform and eventual failure of the mission. While conventional approaches in autonomous navigation favor obstacle avoidance strategies, recent work showed that collision-robust flying robots could hit obstacles without breaking and even self-recover after a crash to the ground. This approach is particularly interesting for autonomous navigation in complex environments where collisions are unavoidable, or for reducing the sensing and control complexity involved in obstacle avoidance. This paper aims at showing that collision-robust platforms can go a step further and exploit contacts with the environment to achieve useful navigation tasks based on the sense of touch. This approach is typically useful when weight restrictions prevent the use of heavier sensors, or as a low-level detection mechanism supplementing other sensing modalities. In this paper, a solution based on force and inertial sensors used to detect obstacles all around the robot is presented. Eight miniature force sensors, weighting 0.9g each, are integrated in the structure of a collision-robust flying platform without affecting its robustness. A proof-of-concept experiment demonstrates the use of contact sensing for exploring autonomously a room in 3D, showing significant advantages compared to a previous strategy. To our knowledge this is the first fully autonomous flying robot using touch sensors as only exteroceptive sensors

Concept, Development and Testing of Mars Rover Prototypes for ESA Planetary Exploration

This paper presents the system architecture and design of two planetary rover laboratory prototypes developed at the European Space Agency (ESA). These research platforms have been developed to provide early prototypes for validation of designs and serve ESA’s Automation & Robotics Lab infrastructure as testbeds for continuous research and testing. Both rovers have been built considering the constraints of Space Systems with the sufficient level of representativeness to allow rapid prototyping. They avoid strictly space-qualified components and designs that present a major cost burden and frequently lack the flexibility or modularity that the lab environment requires for its investigations. This design approach is followed for all the mechanical, electrical, and software aspects of the system. In this paper, two ExoMars mission-representative rovers, the ExoMars Testing Rover (ExoTeR) and the Martian Rover Testbed for Autonomy (MaRTA), are thoroughly described. The lessons learnt and experience gained while running several research activities and test campaigns are also presented. Finally, the paper aims to provide some insight on how to reduce the gap between lab R&D and flight implementation by anticipating system constraints when building and testing these platforms

Sex differences in functional outcomes of intravenous thrombolysis among patients with lacunar stroke.

BACKGROUND This study aimed to assess if there are sex differences in the functional outcome of intravenous thrombolysis (IVT) among patients with lacunar stroke (LS). METHODS Consecutive patients admitted from 1 January 2014 to 31 January 2020 to hospitals participating in the Swiss Stroke Registry presenting with LS and treated with IVT were included. The study population was then divided into two groups based on patient sex, and a multivariable ordinal logistic regression analysis was performed to uncover sex differences in the modified Rankin Scale (mRS) score at 90 days after stroke. RESULTS A total of 413 patients with LS were treated with IVT: 177 (42.9%) women and 236 (57.1%) men. Women were older than men (median age 74 years, 25th-75th percentiles 67-84 years versus 70 years, 25th-75th percentiles 60-80 years, value of p 0.001) and, after adjustment for meaningful variables, showed more frequently increased odds of a higher mRS score at 90 days after stroke (adjusted odds ratio 1.49, 95% confidence interval 1.01-2.19, value of p 0.044). CONCLUSION This study showed that female sex increased the odds of a worse functional response to IVT in patients with LS. Future studies should further elucidate the mechanisms underlying such sex differences

Bi-allelic genetic variants in the translational GTPases GTPBP1 and GTPBP2 cause a distinct identical neurodevelopmental syndrome

: The homologous genes GTPBP1 and GTPBP2 encode GTP-binding proteins 1 and 2, which are involved in ribosomal homeostasis. Pathogenic variants in GTPBP2 were recently shown to be an ultra-rare cause of neurodegenerative or neurodevelopmental disorders (NDDs). Until now, no human phenotype has been linked to GTPBP1. Here, we describe individuals carrying bi-allelic GTPBP1 variants that display an identical phenotype with GTPBP2 and characterize the overall spectrum of GTP-binding protein (1/2)-related disorders. In this study, 20 individuals from 16 families with distinct NDDs and syndromic facial features were investigated by whole-exome (WES) or whole-genome (WGS) sequencing. To assess the functional impact of the identified genetic variants, semi-quantitative PCR, western blot, and ribosome profiling assays were performed in fibroblasts from affected individuals. We also investigated the effect of reducing expression of CG2017, an ortholog of human GTPBP1/2, in the fruit fly Drosophila melanogaster. Individuals with bi-allelic GTPBP1 or GTPBP2 variants presented with microcephaly, profound neurodevelopmental impairment, pathognomonic craniofacial features, and ectodermal defects. Abnormal vision and/or hearing, progressive spasticity, choreoathetoid movements, refractory epilepsy, and brain atrophy were part of the core phenotype of this syndrome. Cell line studies identified a loss-of-function (LoF) impact of the disease-associated variants but no significant abnormalities on ribosome profiling. Reduced expression of CG2017 isoforms was associated with locomotor impairment in Drosophila. In conclusion, bi-allelic GTPBP1 and GTPBP2 LoF variants cause an identical, distinct neurodevelopmental syndrome. Mutant CG2017 knockout flies display motor impairment, highlighting the conserved role for GTP-binding proteins in CNS development across species

Relative Burden of Large CNVs on a Range of Neurodevelopmental Phenotypes

While numerous studies have implicated copy number variants (CNVs) in a range of neurological phenotypes, the impact relative to disease severity has been difficult to ascertain due to small sample sizes, lack of phenotypic details, and heterogeneity in platforms used for discovery. Using a customized microarray enriched for genomic hotspots, we assayed for large CNVs among 1,227 individuals with various neurological deficits including dyslexia (376), sporadic autism (350), and intellectual disability (ID) (501), as well as 337 controls. We show that the frequency of large CNVs (>1 Mbp) is significantly greater for ID–associated phenotypes compared to autism (p = 9.58×10−11, odds ratio = 4.59), dyslexia (p = 3.81×10−18, odds ratio = 14.45), or controls (p = 2.75×10−17, odds ratio = 13.71). There is a striking difference in the frequency of rare CNVs (>50 kbp) in autism (10%, p = 2.4×10−6, odds ratio = 6) or ID (16%, p = 3.55×10−12, odds ratio = 10) compared to dyslexia (2%) with essentially no difference in large CNV burden among dyslexia patients compared to controls. Rare CNVs were more likely to arise de novo (64%) in ID when compared to autism (40%) or dyslexia (0%). We observed a significantly increased large CNV burden in individuals with ID and multiple congenital anomalies (MCA) compared to ID alone (p = 0.001, odds ratio = 2.54). Our data suggest that large CNV burden positively correlates with the severity of childhood disability: ID with MCA being most severely affected and dyslexics being indistinguishable from controls. When autism without ID was considered separately, the increase in CNV burden was modest compared to controls (p = 0.07, odds ratio = 2.33)

Bi-allelic Mutations in NDUFA6 Establish Its Role in Early-Onset Isolated Mitochondrial Complex I Deficiency.

Isolated complex I deficiency is a common biochemical phenotype observed in pediatric mitochondrial disease and often arises as a consequence of pathogenic variants affecting one of the ∼65 genes encoding the complex I structural subunits or assembly factors. Such genetic heterogeneity means that application of next-generation sequencing technologies to undiagnosed cohorts has been a catalyst for genetic diagnosis and gene-disease associations. We describe the clinical and molecular genetic investigations of four unrelated children who presented with neuroradiological findings and/or elevated lactate levels, highly suggestive of an underlying mitochondrial diagnosis. Next-generation sequencing identified bi-allelic variants in NDUFA6, encoding a 15 kDa LYR-motif-containing complex I subunit that forms part of the Q-module. Functional investigations using subjects' fibroblast cell lines demonstrated complex I assembly defects, which were characterized in detail by mass-spectrometry-based complexome profiling. This confirmed a marked reduction in incorporated NDUFA6 and a concomitant reduction in other Q-module subunits, including NDUFAB1, NDUFA7, and NDUFA12. Lentiviral transduction of subjects' fibroblasts showed normalization of complex I. These data also support supercomplex formation, whereby the ∼830 kDa complex I intermediate (consisting of the P- and Q-modules) is in complex with assembled complex III and IV holoenzymes despite lacking the N-module. Interestingly, RNA-sequencing data provided evidence that the consensus RefSeq accession number does not correspond to the predominant transcript in clinically relevant tissues, prompting revision of the NDUFA6 RefSeq transcript and highlighting not only the importance of thorough variant interpretation but also the assessment of appropriate transcripts for analysis

Five-year results following regenerative periodontal surgery with an enamel matrix derivative in patients with different smoking status.

OBJECTIVE To evaluate the five-year results following regenerative periodontal surgery of intrabony defects using an enamel matrix derivative (EMD) in patients with different smoking status. METHOD AND MATERIALS The dental records of patients treated with regenerative periodontal surgery with EMD between 2001 and 2011 were screened. The clinical parameters at baseline (T0) and 6 months (T1) and 5 years (T2) after surgery were collected and analyzed in relation to patient's smoking status (smokers, former smokers, and nonsmokers). RESULTS A total of 71 sites were initially assessed in 38 patients. In total, 56 sites could be evaluated at T1, and 34 after 5 years (T2). At 6 months after surgery, a statistically significant mean probing pocket depth (PPD) reduction of 2.91 ± 1.60 mm and a mean clinical attachment level (CAL) gain of 1.89 ± 1.90 mm were measured. Nonsmokers revealed a greater, statistically not significant CAL gain compared to smokers (2.38 ± 2.12 mm vs 1.50 ± 1.71 mm). Although at 5 years the site-specific PPD values remained stable in nonsmokers, smokers showed an increase of 1.60 ± 2.41 mm. CONCLUSIONS The present study provides evidence that regenerative periodontal surgery with EMD may lead to clinically relevant improvements even in smoking patients. However, the positive effect of EMD seems to be limited in time and can only partially compensate for the negative influence of smoking

The Katwijk beach planetary rover dataset

This paper describes a dataset collected along a 1 km section of beach near Katwijk, The Netherlands, which was populated with a collection of artificial rocks of varying sizes to emulate known rock size densities at current and potential Mars landing sites. First, a fixed-wing unmanned aerial vehicle collected georeferenced images of the entire area. Then, the beach was traversed by a rocker-bogie-style rover equipped with a suite of sensors that are envisioned for use in future planetary rover missions. These sensors, configured so as to emulate the ExoMars rover, include stereo cameras, and time-of-flight and scanning light-detection-and-ranging sensors. This dataset will be of interest to researchers developing localization and mapping algorithms for vehicles traveling over natural and unstructured terrain in environments that do not have access to the global navigation satellite system, and where only previously taken satellite or aerial imagery is available. </jats:p

1-year radiological, functional and quality-of-life outcomes in patients with SARS-CoV-2 pneumonia - A prospective observational study

All over the world, SARS-CoV-2 pneumonia is causing a significant short and medium-term morbidity and mortality, with reported persisting symptoms, radiological and lung alterations up to 6 months after symptoms onset. Nevertheless, the 1-year impact on affected patients is still poorly known. In this prospective observational study, 39 patients with SARS-CoV-2 pneumonia were recruited from a single COVID-19 hospital in Southern Switzerland. They underwent a 3-month and 1-year follow-ups. At 1 year, 38 patients underwent functional follow-up through lung function tests and six minutes walking test and submitted SF-12 and SGRQ questionnaires about health-related quality of life. At 1 year most of the patients showed a persistence of the radiological and functional abnormalities and a reduction of the health-related quality of life. Thirty patients (96.8%) still presented some residual abnormalities on CT scans (31 patients at 3 months), though with a general reduction of the lesional load in all lung lobes. Twenty patients (52.6%) had persisting lung function tests impairment, with an overall improvement of DLCO. As concerning the functional status, lowest SpO2 during 6MWT increased significantly. Finally, 19 patients (50%) reported a pathological St. George’s Respiratory Questionnaire, and respectively 12 (31.6%) and 11 (28.9%) patients a pathological Short Form Survey-12 in physical and mental components. At 1-year follow-up SARS-CoV-2 pneumonia survivors still present a substantial impairment in radiological and functional findings and in health-related quality of life, despite showing a progressive recovery